Swimming appliance



March 16, 1943.

Filed June -19. 1939- 2 Sheets-Sheet 1 March 16, 1943.

J. TUMA- 2,313,979 4 SWIMMING APPLIANCE "iled June 19, 1939 Y 2Sheets-Sheet. 2

Patented Mar. 16, 1943 UETED STATE 21 Claims.

This invention relates to improvements in swimming appliances and moreparticularly concerns a novel device to be applied tothe hand of aswimmer to serve as a paddle blade or artifical web which will aid inattaining greater swimming speed and efliciency.

Prior devices of this character have generally proven unsatisfactoryfor. a number of reasons, perhaps outstanding among which may bementioned improper proportioning relative to the users hand, lack ofadaptability for diiferent swimming uses, failure to provide adequateprecautions against accidental injury from the hard structures of thedevices, and generally inadequate arrangement.

It is an object of the present invention to provide a swimming appliancewhich is properly proportioned with respect to the swimmers hand toafford maximum swimming aid coupled with proper balance of thepropulsive area thereof relative to the muscular center of the hand,whereby the swimmer attains greatly increased capacity for propulsionthrough the water without undue fatigue or muscular strain, and in anyevent without placing unequal demand upon the muscles of any portion ofthe hand.

Another object of the invention is to provide a swimming appliance thatis readily adjustable to accommodate variations in the sizes of swimmershands as well as to permit alterations in the propulsive area of theappliance for various swimming purposes, thus permitting, for example,an increased propulsivearea for distance swimming where a relativelylong, powerful stroke is most advantageous, and a reduced propulsivearea for short, quick strokes in speed swimming or for stunt maneuvers.

Still another object is to provide novel means for efiecting adjustmentof such an appliance.

A further object of the inventionis to-provide a swimming appliancehaving safety features which will avoid possible injury to the swimmeror others from carelessness negligence, accident or inexperience in theuse or handling of the appliance, as where the appliance comes againstan exposed part of a persons body in such a manner and with such forceas would ordinarily lead to injury from an unprotected relativelyunyielding object.

Yet another object is to provide a swimming appliance which maybefreelyreleased from the swimmers hand either in or out of the waterwithout loss and in such a manner as to permit quick, unassistedreplacement of the device upon the hand for use.

A still further object of the invention is to provide a swimmingdevicewhich embodies a relatively inexpensive and highlyv efficient working as mbl f c parati e y light we ht but strongand durable construction andwhich may be produced at low cost.

Other objects and advantages will become apparent in the followingdescription and from the accompanying drawings in which:

Figure l is a perspective view of a swimming appliance embodying theprinciples'of the invention.

Fig. 2 is a transverse sectional view taken substantially along line2--2 of Fig. 1.

Fig. 3 is a longitudinalisectional view through the appliance takensubstantially along line 3-3 of Fig. l.

Fig. 4; is aninside face view of the, appliance.

Fig, 5, is a back-face View of a slightly modified form, of theappliance. M

Fig. 6 is a transversesectional view taken substantially in the plane ofline 6-6 of Fig; 5.

Fig. '7 is a fragmentalexploded assembly view of the separating devicerortha pnanee shown H &5

Fig. 8 is a longitudinal sectional view talgen substantially along line8" -8 of Fig. 5.'

' Fig. 9'is an inside-face view ofthe' appliance shown in Fig. 51

Fig. 10 is an enlarged sectionalview taken substantially in the plane'of'line Hl--l ll'of Fig. 5.

'While the invention is susceptible of various modifications and"alternative constructions, I have shown in the drawings and will hereindescribefiri detail, certain preferred embodiment s but it'i's' tobe'unde'rst ood that I do not thereby intend to limit the revenues tothe specific forms "jdisclosed, but intend to cover all modificationsand alternative constructions falling within the spirit and scope "ofthe invention as 'egr'pressed in the appended claims.

Generally speaking, mesw mmmg appliance of the present'inventionprovides apad'dle blade or shell which is adapted to be suitably securedflatwise against the inside 'of "a swimmers hand to increase the water"resistance or propulsive area thereof and thus" aid in propelling theswimmer through the water. The appliance is adjustable to vary theoverall pressure or propulsive area thereof to make itadaptable fordifierent swimming requirements and for accommodating hands of varioussizes. Moreover,

the relatively rigid or hard parts of the structure areprovided with ayieldable coating or buifer which will avoid the danger of injuring theperson of the swimmer or others who might come in contact with theappliance in a manner which would ordinarily have a damaging efiect.While in use, the appliance is held firmly in place on the hand, but thehand may be freed easily and quickly when necessary while retaining theappliance in such relation to the hand by means of a wrist anchor thatthe appliance can be readily replaced upon the hand without specialassistance. Such wrist anchor avoids loss when the appliance is removedfrom the hand in the water.

Referring now to Figs. 1 to 4 of the drawings, a right-hand swimmingappliance l5 embodying the present invention is shown as having agenerally flattened body of substantially ovate outline which is adaptedto be received flatwise against the inside of a swimmers hand which isindicated generally in Figs. 1 and 4 by the phantom outline I 6. I havefound that where the pressure center of the appliance, represented bythe crossed lines I! in Fig. 4, substantially coincides with themuscular center of effort of the hand, and the planular dimensions ofthe appliance are kept fairly close to those of the hand, a balanced andefiicient relationship is attained that avoids undue fatiguing or unevenstrain or stress upon any portion of the hand during swimming when theappliance is forced face-wise through the water. To this end the lengthof the appliance is preferably such that it extends from the wrist tonot substantially beyond the tips of the fingers, and the width of theappliance is not substantially greater than the width of the hand. Inpractice it has been found best normally to avoid more than generallyone-half inch projection of the appliance beyond either the end or thesides of the hand, and any such projection should preferably be uniformall around the hand. A left-hand unit (not shown) is constructedidentically except for the necessary rearrangement of parts toaccommodate the left hand, and in practice the swimmer will use one ofthe units on each hand. Moreover, the appliance l5 may be constructedfor any general hand size ranges, as for example, juvenile, ladies andmens sizes.

According to the present invention the appliance I5 is preferablyconstructed for adjustment as to width and for this purpose the bodythereof comprises a pair of generally elongated plate members [8 and I9which are connected in overlapping relation by means of a suitable pivotmember such as a rivet passing through the plates adjacent to the wristends thereof. The plate I 8 which may be referred to as the backplate,is preferably the larger of the two and is adapted to be received by theinside of the hand substantially as indicated in Fig. 1, The other platel9 may be termed the fore-plate and is of smaller area than theback-plate l8, being adapted to lie a ainst the inside face of thebackplate and generally within the peripheral outline thereof. Bothplates may be slightly arcuate in shape longitudinally to conformgenerally to the normal, comfortable arc of the inside of the hand whileswimming.

To increase the effective propulsive area of the appliance it is merelynecessary to spread the plates apart fanwise into any of a plurality ofselective positions of adjustment substantially as indicated in Fig. 4which shows in dash outline 'A an intermediate adjusted relationship,and in dot-dash outline B the fully spread relaticnship of the plates.Such spreading of the plates will also serve in certain cases toaccommodate the appliance to a larger than normal hand of the class forwhich the appliance has been designed. Preferably, the spreading of theplates will carry the fore-plate I9 beyond the thumb side of theback-plate I8 so that the thumb bearing against the protracted portionof the fore-plate l9 will maintain proper balance between the increasedpropulsive area of the appliance and the muscles of the hand. It mayalso be noted in this connection that the shape of the fore-plate I9 isdesigned to maintain, in any adjusted condition of the plates, as nearlyas practicable a balanced relationship with respect .to the hand both asto weight and propulsive area. Moreover, the plate-connecting pivot 20is preferably located near the thumb side of the appliance so that notonly the finger portion but also the palm portion of the propulsive areaof the appliance will be modified by relative planular shifting of theplates l8 and I9. In any event, the arrangement of the plates ispreferably such that in the spread adjustments thereof the center of theaggregate propulsive area follows and in all instances substantiallycoincides with the muscular center of the hand which is proportionallyspread or adjusted in its position to maintain adequate purchase uponthe spread plates. The shifted center of the appliance in each of theadjusted conditions A and B of the plates is shown in Fig. 4 at H andI1, respectively.

The various conditions of adjustment of the appliance may be maintainedfixedly by suitable means such as a slot and bolt connection including aknurled thumb nut 2| threaded onto a bolt 22 which in the presentinstance extends through and is non-rotatably fixed within a perforation23 in the back-plate !8, the shank of the bolt projecting through anelongated slot 24 in the fore-plate IS. The slot 24 is formed on an arcradially with the pivot 20 so as to form a free way for travel of thebolt 22 between the ends of the slot which serve as limiting stopsdetermining the fully closed and fully spread conditions of the plates.Although not illustrated herein, it may be pointed out that theappliance has also been constructed with the slot 24 in the back-platel8 and the belt 22 projecting from the fore-plate l9, such relationshipbeing fully equivalent in the holding function of the contrivance. Thus,when the thumb nut 2| is loosened, the plates can be adjusted and thenfixed in the selected adjusted relationship by tightening the thumb nutagainst the adjacent slotdefining portions of the slotted plate.

Means serving to aid in holding the plates in adjusted relationship maycomprise a plurality of mating undulations providing shallow ribs 25formed in the plates [8 and I9 to intersect the adjustment slot 24.After the securing nut 21 has been tightened the ribs provide aninterlock holding the plates against slipping out of adjustment. In thepresent instance the ribs 25 are formed to extend radially from a centersuch as the pivot 23 near the wrist end of the appliance and broaden outtoward the edges of the plates l8 and I9 roughly in simulation of asea-scallop shell, thus imparting an attractive appearance to theappliance.

In the preferred construction, the ribs 25 of each of the body plates l8and I9 are formed in a foundation or core member 26 of suitable sheetmetal or other preferred relatively hard material; and a resilientcovering 21, such as rubber which partially or wholly encases the coremember, completes and emphasizes the ribbed structure proved withrespect to; the nut 21 by. channeling the rubber casing 21 around theslot '24. The frictionaLengagement between the rubber at the interfacebetween the plates when theilatter are secured in adjustment aids inholding the plates inadjusted condition. To maintain a suitableseparation of the rubber interfaces of the plates adjacent to the pivotso as to assure freedom of pivotal adjustment of the plates, anysuitable expedient may be employed, such as abutting spacer flanges 21formed integral with the core plate 26 encircling the pivot rivet 20.

By reference to Fig. 2 it will be seen that the ribs 25 are fairlypronounced on the propulsion .face as well .as the back face of thedevice, and

extend from the forward end to the rear portion of the plate structure.This places ,a pluralityof impedances to the free flow of water alongthe surfaces of the plate crosswise of the ribs, and results in holdingthe device against side slip in the water while in use. Thereby maximumpropulsive effect is obtained from each swimming stroke, since little ifany effort is wasted by side slip.

The rubber casing?! also serves in thepresent instance as a resilientprotective buifer for avoiding injury to the person of an individual whomight .be struck by or come in contactwith the appliance -in such amanner that the unprotected, relatively hard core members 25-mightordinarily cause damage. To this end, the'rubber-casing ispreferablyextended substantially :beyond the edges .of the core members 25 and isformed witha smoothly finished bead 28.

To maintain the appliance it": upon the hand l6, suitable means such asa strap 29 of fabric or other material in the form of a band,adjustable-by means of a buckle'SB, is carried by the .backsplate l8. Inthe present instance the strap is threadedloosely through a of elongatedspaced parallel strap loops 3| which are struck out integrally from thebody of the back-plate is to, project from the back face of the latterrearwardly of the transverse center of such plate.

One .of thestrap loops 3! is located near the little finger edge of theback-plate andthe outside spacing of these loops is approximatelyequivalent to the width of the palm of the hand between the littlefinger and thumb crotch sides thereof so that the loops will underliethe hand and permit substantially full encircling engagement of the handby the strap 29 which extends slightly be- .yond' the sides of theloops. In order to permit lateral shifting ofthe strap 29 in the'loops3i .as-for accommodating adjustments in the posi tion of the hand whenthe appliance is adjusted in area, the loops-are preferably about twiceas long as the width-of the strap'and are located somewhat out ofalinement as shown in Fig. 4, the loop at the little finger side beingdisposed forgether.

.merely by releasing the thumb grip .tionof-the strap being shown inFig. 4 at 29 and 29",- respectively. Moreover, the location of-theloops: 3| is such,.10ngitudinally oft-he appliance, that the strap 23will engage across the back of the hand firmly behind the knuckles.

When the hand is engaged within the strap '29, the thumb is free toengage a thumb grip indicated generally by the numeral 32 (Figs. 1

and 10), which is preferably mounted upon the backface of the fore-plateI? in general alinement with the strap 29 and in position to enter the.thumb crotch of the hand and receive the inner. joint of the thumb. Asuitable notch 33 in the adjacent edge of the back-plate l8 accommodatesthe thumb grip when the plates are in fully collapsed relation.

In the preferred construction, the thumb grip 32- includes a swivelledbase member 34 (Figs. 1 and 10) which is pivotally connected to theforeplate l9. as by a swivel rivet 35. A longitudinallyarcuate'thumb-receiving member 31 is hingedly connected to the basemember so that when the appliance is not in use the thumb grip may becollapsed substantially as shown in broken outline in Fig. 10 and thusavoid any projection that might injure a person accidentally sitting orstepping upon the appliance. As shown, the hinge for the two members maybe of substantially the piano type, the base member 34 having a pair of.spaced coaxial loops 3% at its inner end terminating in reverse bent,upwardly extending hook-shaped stops 39. A hinge pin 40, extendingthrough the loops 33 and a central hinge loop 4| (Figs. 1 and 5) on theinner end of the thumbreceiving member'3l, connects the members to- Apair of heels 42 on the inner end of the thumb-receiving member 31 atopposite sides of the loop 4| are adapted to seat within the hooks ofand engage against the respective stops 39 in the fully opened orthumb-receiving relationship of the thumb grip members.

The center of mass of the thumb-receiving member 31 is preferablydisposed outwardly relative to the axis of the hinge so that the member31 will normally tend to fall into the collapsed position. A protectiverubber buffer coating 43 on the member 37 will aid in securing theoverbalanced relation. Due to the swivel mounting of the thumb grip 32it will automaticallyassume the proper position to accommodate the thumbin any condition of adjustment of the plates l8 and I9 as shown in Fig.4.

"If the hand strap'29 is not drawn too tightly, the appliance I5 can beremoved from the hand and stretching the hand to disengage and slip itfrom the strap. At times such removal may have to be effected quickl tofree the hand at least momentarily for other uses and under suchconditions that attention may not be given to what becomes of theappliance. It is therefore desirable to provide means which will permiten-- tire freedom of the disengaged hand but will retain the-applianceon the swimmers arm and avoidthe necessity for holding onto or discarding the appliance in the interim between disengagement and reengagementthereof. To this To maintain the secured end of the tape at out 1 ofrubbing engagement or interference with the hand or the wrist theeye-containing portion'of the wrist end of the back-plate is formed asan inwardly angled flange 48. This flange 48 also carries the propulsivearea of the appliance well back toward the wrist while leaving completefreedom for wrist movement.

The form of the invention shown in Figs. 5 to 9, inclusive, is generallythe same as that already described, with the exception that a differenttype of adjustment-securing means is employed for the adjustable bodyplates I8 and I9, and that the core member 26' of both the body platesis without undulations, so that the inner faces of the plates appearrelatively smooth as shown in Fig. 9, while ribs 25' are formed on theback face of the back-plate l8 only by suitable molding of the rubbercoating 21. To facilitate pivoting of the plates i8 and IS, the coremembers 26 are spaced apart at the pivot 29 by a washer or spacing ring20".

The adjustment-securing means in this form of the invention comprisessuitable riveted snap fasteners including male members 49 secured to andprojecting from the fore-plate I 9' and female members 50 secured to theback-plate l8 to register with and grip the male members. Herein, thesnap fasteners are arranged to provide a plurality of adjustedpositions, shown as three in number, there being three pairs oflongitudinally spaced male members 49 located on the radii of the pivotpoint 20 of the body plates and equally spaced apart laterally of theappliance with the front and rear members 49 respectively located oncommon arcs concentric with said pivot point. One pair of the malemembers 49 is adjacent to the thumb edge of the plate l9 while anotherpair is adjacent to the opposite or little finger edge and the remainingpair occupies an intermediate position. Only one pair of the femalemembers 50 need be provided on the back-plate I 8' and is adapted toregister with any of the selective pairs of male members 49 The femalemembers 50 are preferably mounted in such relation adjacent to the thumbedge of the backplate l5 that in either the intermediate or fully openadjusted positions of the back-plate said thumb edge will clear theadjacent exposed male members.

In order to permit the plates l8 and E9 to approach closely togetherafter the snap fasteners have been secured, the female members 55 arepreferably secured within inwardly opening hollow nodes 5| which projectfrom the back face of the back-plate I3, there also being additionalpairs of the nodes 5| to receive the unengaged projecting pairs of malemembers 49 at the interface between the secured plates (Figs. 5 and 6).Preferably, the nodes 5| and the prominences of the ribs 25 aregenerally related to project from the back face of the plate I8approximately equally so as to cover up the protuberance of the nodesand blend them harmoniously into the shell-simulating surface of theappliance.

Due to the strong holding qualities of the snap fasteners and theclosely adjoining relationship of the plates, it is difi'icult to effectunaided separation of the snap fasteners without injury to therelatively thin body plates I8 and IQ of the appliance Novel means istherefore provided for effecting such separation easily, quickly andwithout danger of damaging any of the structure, herein comprising amanipulable device including means located between the interface of theplates and adapted by a simple manipulation exteriorly of the plates toapply a separating force therebetween axially of the snap fasteners.Herein, a

generally flat, stamped metal lever 52 is provided which extendsswingably partially between the plates [8' and I9 through a suitableslot 53 formed in the back-plate l8 intermediate the female members 50of the snap fasteners Dividing the lever 52 into an inner or separatorportion 54 and a slightly larger outer or handle portion is a transverseangularly bent fulcrum portion 56 of a width to offset the separator andhandle portions sufiiciently to accommodate the thickness of theassociated area of the back-plate l8 and permit the separator and handleportions to lie inactively against the respective faces of theback-plate.

A simple expedient for maintaining the lever in assembled relation withthe back-plate consists in forming the slot 53 shorter than the width ofthe lever so that the plate areas adjacent the ends of the slot may bestraddled by the opposed shoulders defining locating notches 51 formedin opposite sides of the lever at the end of the fulcrum portion 56thereof. In assembling the lever 52 with the back-plate IS, theseparator portion 54 is inserted into an enlargement of the slot 53effected by bending a triangular flap 53 (Fig. '7) out ofthe plane ofthe back-plate along a slit 59 running a suitable distance inwardly fromone end of the slot, the flap being returned into the plane of theback-plate at the conclusion of the assembly operation to lock the leverin swingable operative position.

The separator portion 54 of the lever is thin enough to lie within anarrow clearance between the plates and is preferably of generally spadeshape, having the inner extremity rounded off where it engages thefore-plate l9. While inactive, the handle portion 55 lies within theplane of the adjacent nodes 5| from which position it may be digitallyraised to actuate the device, the outer extremity of the handle beingpreferably turned up to facilitate the digital engagement.

When the snap fasteners are to be separated to permit the fanwiseadjustment of the plates l8 and l 9, the handle 55 of the separatinglever is raised from its reclining position to swing the lever about itsfulcrum. By this action the extremity of the separator is caused to bearagainst the fore-plate l9 and the shoulders of the separator to bearforcibly in the opposite direction against the inside of the back plate,substantially as shown in full outline in Fig. 8, to force the platesapart such a distance that the fasteners will be caused to snap apart.It may be noted that the angle of the fulcrum portion 56 of the leverand the width of the notches 51 are such that in the fully extendedcondition of the lever, the separator 54 and the handle 55 will be at adiagonal angle short of attaining a perpendicular relation to theseparated plates. Due to this diagonal position of the lever and theoverbalanced construction thereof, the lever will tend when released toreturn promptly to inactive position as shown in broken outline in Fig.8 and thus permit free relative adjustment movement of the plates andresecuring of the snap fasteners in the selected adjusted position.

From the foregoing it will be apparent that the present inventionprovides a new and improved swimming appliance which is properlybalanced and proportioned with relation to the swimmers hand to attainutmost efiiciency'in swimming power without muscular strain or un- Bythe novel adjustable relationdue fatigue. ship of the body plates of theappliance, various conditions may be adequately met as to swimmers handsizes and preferred propulsive area of the device. Substantial aid andconvenience in attaining and maintaining various selective adjustedrelationships of the plates of the appliance are assured by the novelsecuringmeans provided therefor. Moreover, the resiliently bufferedconstruction of the device assures safety from personal injury to theuser as well as others since there are no exposed parts which might ifunprotected prove damaging under certain circumstances such as beingstruckthereby. Another desirable feature is the anchorage of theappliance to the swimmers wrist so that the hand may be freely releasedwithout discarding the'appliance. Furthermore, the appliance is ofstrong and durable construction and may be produoed at low cost.

I claim as my invention:

1. A swimming appliance comprising, in combination, a body structureincluding a pair of overlapped plates adapted for adjustment to vary thepropulsive area of the appliance, means for securing said plates inselected relative positionsoffixed adjustment to determine thepropulsive area of the appliance, and means for preventing slippage ofsaid plates after they have been secured in any such adjusted positions.

2. A swimming appliance of the character described comprising', incombination, a body structure including a pair of overlapping platesadapted to be spread apart to vary the propulsive area of the body,means for securing the plates in adjusted relationship, and a pluralityof longitudinal interfitting ribs on the opposed faces of said platesproviding an interlock in the secured condition of the plates to preventaccidental spreading of the latter.

3. A swimming appliance comprising, incombination, a flattened bodycomprisinga pair of overlapping plates adapted for planular adjustmentto vary the propulsive areaof the body, means for securing the plates invarious positions of relative adjustment, said means includingportions-thereof protruding from the face of one of said plates, and aseries of ribs on said face providing a pattern into which saidprotruding-portions tend to blend.

LA swimming appliance comprising, in combination, a propulsion bodystructure comprising a pair of overlapping relatively adjustable plates,and snap fastener means carried by said plates for securing said platesin a plurality of selected positions of relative adjustment.

5. A swimming appliance comprising, in combination, a pair ofoverlapping plates, a snap fastener for securing said plates inface-to-face relationship, one of said plates having a slot therein, aplate-separating lever projecting partially through said slot havinglocating means engageable with the opposite faces of said one plateadjacent to said slot, an angular fulcrum portion dividing said leverinto an inner separator'pcrtion and an outer offset handle portion andbeing engageable with an edge defining said slot, the oifsetrelationship of saidseparator and handle portions being sufiicient toaccommodate the thickness of the adjacent part of said one plate andenable said portions to lie inactively against the inside and outsidefaces respectively of such plate, saidseparator portion being shaped toengage the opposed faces of both of said plates to force the latterapart when said handle portion'is manipulated to swing the lever out ofthe inactive position about the fulcrum.

6'. Acombination including;a pair of separable device extending throughsaid opening including means tobemanipulat'ed for actuating thedeviceand means between the plates adjacent to the snap fastener forforcing the plates apart torelease the snap fastener when saidmanipulating means is actuated.

7. A'combination includinga pair of separable plates, a snap fastenersecuring said plates in close face-to-face relationship, and a separatorbetween said plates including a part exposed for manipulation to actuatethe saparator and force said plates apart by. pressure exerted axiallyof said snap fastener for releasing the latter.

8. A swimming appliance comprising, in combination, a propulsion platestructure, means for connecting said plate structure to a swimmers hand,and athumb grip on said plate structure comprising a pivotedthumb-engaging member adapted When engaged by the thumb to be held inprojecting relation to the plate structure and when outof thumbengagement to lie in a collapsed pcsition close to the plate structure.

9. A swimming appliance of the character described comprising, incombination, a body member adapted to rest against the palm of aswimmers hand and including a fore-plate and a back-plate connectedtogether pivotally for relative fan-wise adjustment to modify the areaof the body member, means for holding said plates relatively fixedly inselected adjusted relation, a strap to engage behind the hand,.and meansloosely attaching said strap to said back plate to permit limitedshifting movement of the entire strap in a front to rear directionrelative to the back plate to accommodate adjustments in the position ofthe hand when the area of said body is adjusted.

10. In combination in a swimming appliance of the character described, abody plate structure, a strap extending across the plate structure forholding the latter against the palm of the swimmers hand, and a pair ofloop members at the-respective opposite sides of the back of the platestructure having the strap engaging loosely therethrougn for connectingsaid strap in place, said loop members being longer that the width ofsaid strap to permit lateral shifting of the strap lengthwise of theloop members.

11. A swimming appliance comprising, in comination, a body structureincluding a pair of overlapping plates pivotally connected adjacent tothe wrist end of the structure for planular adjustment fanwise'to varythe'propulsive area of the body, and slot and bolt means adjacent to thefinger end of the body structure for securingsaidplates in variouspositions of relative adjustment, the'slot of said means extending onvthe radius of the adjustment pivot of the plate;

12'. In combination in a swimming appliance of the character described,a pair of overlapping plates forming a body structure, longitudinalinterfitting ribs on said plates, and means for connecting said platesreleasably together permitting'relative adjustment thereof to controlthe propulsive area of the body structure comprising a slot extendingacross the ribs of one plate and a fastening member carried bythe otherplate and extending through said slot, said ribs tending, to hold theplates against accidental spreading when the connecting means is fastand holds the plates together.

13. A swimming appliance of the character described, comprising, incombination, a backplate dimensioned longitudinally and transversely notsubstantially greater than the hand of a swimmer of a general class withthe thumb and finger closed, the center of the propulsive area of saidback-plate substantially coinciding with the center of muscular effortof the hand lying palmwise against the back-plate, a fore-platedimensioned to lie in substantially entirely overlapped relation to saidback-plate, means connecting said plates together pivotally adjacent tothe wrist end of the appliance and near the thumb side of the plates insuch a manner that as the plates are spread fanwise toward the thumbside of the appliance, whereby to increase the propulsion area, theshifted center of the enlarged propulsion area will substantiallycoincide with the center of muscular effort of the hand as the thumb andfingers are spread over the enlarged area, and means spaced from theforward end of the plate for connecting the plates relatively fixedlytogether against one another in any of a plurality of selectivepositions of adjustment.

14. A swimming appliance of the character described comprising, incombination, a body structure adapted to be received against the palm ofa swimmers hand and including a back-plate and a fore-plate, meanspivotally connecting said plates together adjacent the wrist end of thebody structure for fanwise adjustment to modify the propulsive area ofthe body structure, a thumb grip carried by the thumb side of saidfore-plate and having a swivel mounting enabling swinging thereof toconform to adjustments of the thumb position as the plates are adjusted,at hand engaging strap carried by the back-plate, and attachment meanson said back plate loosely engaged by the strap, said strap being freelyshiftable on said attachment means within a limited range longitudinallyof the body structure to accommodate adjustments in position of the handfor the difierent adjusted positions of the plates.

15. A swimming appliance comprising, in combination, a body platestructure adapted to be received against the palm of a swimmers hand andhaving longitudinal and transverse dimensions closely approximating theoutline of the closed hand so as to avoid substantial extension beyondany part of the hand whereby the center of the propulsion area of thestructure is substantially coincident with the center of muscular elfortof the hand, a strap for holding the plate structure in palm contact,means on said plate structure for connecting said strap thereto in alocation to engage across the back of the hand and including aconnecting member close to the little finger edge of the plate structureand a second connecting member spaced inwardly from the thumb edge ofthe plate structure adjacent to the position assumed by the thumb crotchof the hand, and a thumb grip carried by the thumb margin of the platestructure in alinement with said strap transversely of the platestructure in substantially the position normally taken by the thumb whenthe hand is in centered and balanced relation on the plate structure,said thumb grip being wholly open on the side away from said strap sothat the thumb can be released therefrom instantly as for removing thehand from the appliance.

16. A swimming appliance of the character described comprising, incombination, a body structure including a pair of overlapping platesadapted to be received against the inside of a swimmers hand and adaptedto be spread apart adjustably to vary the propulsive area of thestructure, and releasable means for securing said plates fixedly againstone another in various selected relative positions of adjustment todetermine said propulsive area, said means upon being released from theplate securing relationship allowing the plates to be readjusted byrelative movement in their planes to alter said propulsive area.

17. A swimming appliance of the character described comprising, incombination, a propulsion structure to be held in a swimmers handincluding a fore-plate and an overlapping back-plate pivotally connectedtogether adjacent to the wrist ends thereof for fanwise adjustment tomodify the effective propulsive area of the structure, re-

leasable means for securing said plates relatively fixedly in variouspositions of such adjustment, means on said back plate for engaging theswimmers hand to hold the appliance against the latter, a thumb gripincluding a portion for engagement by the thumb of said hand and a baseresting against the fore-plate, and swivel pivot means securing saidthumb grip base onto the fore-plate in such relation to said handengaging and holding means that when the hand is fully in positiontherein the thumb may naturally engage said engagement portion of thethumb grip, said swivel pivot permitting the thumb grip to swing into aproper thumb receiving position relative to said hand engaging andholding means automatically upon engagement by the thumb in any adjustedrelationship of the plates.

18. In combination in a swimming appliance of the character described, abody comprising a pair of overlapping plate dimensioned for substantialregistration to provide a propulsive area not substantially greater thanthe area of one of the plates alone, a pivotal connection for the platesadjacent to one end of the body adapting the plates to be spread apartfanwise so that the second plate projects laterally partially beyondsaid one plate for increasing the propulsive area of the body inproportion to the area of the projecting portion of the second plate,and releasable mean on said plate adjacent to the opposite end of thebody for securing the plates fixedly together in face to face abutmentagainst fanwise movement from any adjusted relation.

19. A swimming appliance comprising, in combination, a propulsion platestructure, and means for holding said plate structure to a swimmers handincluding a thumb grip comprising a base on the plate structure and athumb-engaging member pivotally connected to said base, said memberhaving its center of weight located laterally of the pivotal axis sothat the normal tendency of the member when out of thumb engagement inan upwardly facing condition of the plate structure and the base is totip over and assume a collapsed position overlying the base.

20. A swimming appliance of the character described oomprising, incombination, a body comprising a pair of plates arranged to fit againstthe palm of a swimmers hand and including a foreplate and an overlappingback-plate pivotally connected together at a point adjacent to the wristends of the plates, said fore-plate being dimensioned to lie inretracted condition substantially entirely inside the edges of said backplate and being adapted to be extended laterally beyond the thumb sideof the back-plate to increase the effective propulsive area of the body,means on said plates for securing the fore-plate against the back-platein retracted position or in selected positions of extended adjustment,means for holding the body against the palm of the swimmers handincluding a thumb grip on the thumb side of the rear face of saidfore-plate, and means for pivotally connecting said thumb grip to theback face of the fore-plate so as to permit swivelling of the thumb gripto accommodate the thumb properly in any adjusted position of thefore-plate, said back-plate having a notch at; the thumb side'thereof toaccommodate said thumb grip in the retracted position of the foreplate.

21. A swimming appliance comprising, in combination, a body platestructure having a. broad propulsion face, means carried by said platestructure opposite the propulsion face for holding the plate structurebroadside against the palm of the swimmers hand, the propulsion face ofsaid plate structure having a plurality of ribs extending in a generallyfront to rear direction from the front to the rear end portions thereofand forming impedances against side slip of the appliance in the wateras it is driven through the water in a propulsion stroke, the ridges ofthe ribs being in substantially the same straight plane projectedtransversely relative to the front to rear axis of the plate structure,whereby each rib will be equally efiective as a side slip impedance.

JAMES L. TUMA.

